Extremely fine pumice experiment was a total success!

[SoapyBenjamin]

Hello, fellow soapers... I'm in an incredibly good mood. Why, might you ask? Because—for the first time—one of my crazy ideas actually produced the results I was hoping for... On the first attempt!

The thought process:

• Instead of the familiar (somewhat) waxy/crayon texture of regular lye-based soap, I asked myself, how does one make the soap texture (wet or dry) a little more "grabby" without any exfoliant scrubbiness?
• I wanted a matte-like texture that had some non-slip properties, but not enough to stop me from bathing... Just enough to not feel like it would shoot out of my hands with a hard squeeze.
• I figured I would try a 2-to-1 ratio of pumice-to-kaolin clay, just in case the pumice turned out to be more exfoliating than I had hoped... It didn't. The pumice is just too fine (around 75 microns)...

I made 8-9 batches of soap (1,000 kg), with slight variances in the recipe, all with the same amount of pumice and kaolin clay—which at first glance, looks like a lot!

I soaped at about 100° F, with a 2:1 water-to-lye ratio, and a 5% superfat.

One of the recipes:

• 31% Coconut oil
• 31% Palm oil
• 31% Olive oil
• 7% Castor oil

Additives (% of oil weight):

• 3% Sorbitol
• 2% Sodium lactate
• 2% Cetyl alcohol
• 3% Sodium citrate
• 0.5% EDTA
• 0.25% ROE (7% CA)
• 4% EO or FO

And... Wait for it...

• 5% Kaolin clay
• 10% #FFFF Pumice

I couldn't be happier... It's almost subliminal (which is exactly what I was looking for). I didn't want people to say, "Hey, this feels like sandpaper." Both my wife and I love it.

Note: I do recommend pouring your batch at a medium/thick trace, however. Clay and extra fine pumice do not sink, but the thicker trace (I feel) ensures an equal distribution. Some good stick blending accomplishes both a faster trace and good distribution.

Where to buy:

• Hess Pumice Products: https://pumicestore.com/pumice-grades-directory.html
• PDF with product info: https://pumicestore.com/PDFs/TDS-Grade-FFFF.pdf

Let me know if you decide to try it and how it works out for you. Thanks!

ETA: No negative effect on lather... The creamier recipes are just as creamy, and the bubblier recipes are just as bubbly as they are without the pumice and clay.

 

[SoapyBenjamin]

Some follow-up thoughts...

• Exfoliation: This pumice/clay recipe is not exfoliating from a sensory perspective. If you're trying to make a "mechanics soap" or a more noticeably exfoliating soap, you'll want to go with a much larger particle size. However, having said that, I believe it might be micro-exfoliating. In other words, it's very likely to have some exfoliating effect at a level you can't feel. FWIW, I love the way it feels on the skin.
• Why kaolin? The addition of kaolin clay might also seem counterintuitive. If I wanted a surface texture that was a little more "grabby," why would I add another ingredient that is known to be "slippy?" Good question... I don't know, but I am reluctant to change the formula because I'm so happy with the result. I suppose I could eliminate the kaolin clay and use less pumice... One day, I may try this.
• Lather: You might have noticed the (slightly higher) use of coconut oil and other bubble-enhancing additives. I wasn't sure if the pumice would act as a "lather killer," so I hedged my bet and adjusted the recipe (ever so slightly) to account for this assumption. It's hard to tell if this made any difference vs. the same recipes without. I didn't notice any difference, and I'm more than willing to keep those adjustments as permanent changes to the recipe.
• Mainstay: Is this addition going to be a part of all my formulas moving forward? Yes... It's that good... IMO. Who doesn't want a differentiator in their formulations?

 

[Firefly24]

Love soap with pumice, so do my customers.

 

[AliOop]

Fantastic! Thank you for the detailed explanation of your thoughts, process, and results.

 

[SoapyBenjamin]

Thanks, @AliOop & @Firefly24... I recently did an experiment with the Ciaglia method for a speckled aesthetic (recent post), in which I still used 10% pumice, but did not use kaolin clay (I ran out). Strangely, although the pumice is still noticeable, it wasn't as pronounced as before. The kaolin somehow augments the "micro exfoliation." I can't wrap my head around this... i.e. why would kaolin clay—an additive used for a soothing texture—help the pumice be more effective. Very strange indeed... Needless to say, I'll be using the 10% pumice and 5% kaolin from now on, as it was consistent across many trial batches.

 

[AliOop]

Maybe the clay is absorbing more of the water, making the bar a bit firmer?

 

[Firefly24]

I made soap with Bentonite clay & pumice. I like Kaolin as well. I am going to sample my soap today.